Apartment house signaling and telephone system



March 12, 1940.

c. AUTH APARTMENT HOUSE SIGNALING AND TELEPHONE SYSTEM 2 Sheets-Sheet 1 Filed July 8, 1938 INVENTOR (Zen/as fii BY M M ATTORNEYS UTH March- 12, 1940.

APARTMENT HOUSE SIGNALINVGJANDTELEPHONE/SYSTEM Filed 'July 8, 1938 2 sheets-sheet};

Patented Mar. 12, 1940 "STAT APARTMENT HOUSE SEGNA LING AND TELEPHONE SYSTEM This invention relates to selective electrical signaling and telephonic intercommunicating systems of a type particularly applicable for installation in apartment houses and the like, and

15::- such that a caller may signal any apartment from an entrance to'thebuilding and thereafter carry on a telephonic conversation with the occupant called.

Although systems of this general character m are known, all previous systems of which I am aware, require the installation in each apartmentin addition 'to the usualtelephone set for carrying on conversation, of a sound producing signaling device, such as an, electrically actuated 1b. bell, buzzer, chime, etc for initially attracting the occupants attention. This requirement of a separate signaling device-in each apartment involves a considerable duplication of equipment, the initial expense of which is large, particularly where signaling devices ofa more refined nature, such as chimes, are provided, as is found to be increasingly necessary in modern buildings to meet the present day demands of tenants. Also the installation of these more expensive signaling devices introduces additional items of expense inasmuch as pilfering is encountered where these devices are mounted in an exposed manner, whereas if the units are built-in to prevent this, especial and expensive precautions are required to assure proper tonal eilects. 'Likewise with the more usual type of telephone set heretofore provided-in such installations wherein the receiver is suspended from a cord, pilfering is also encountered; and such units are, moreover,

unsightly.

In accordance Withiny invention I propose to eliminate this duplication of equipment, loss through pilfering and the unsightliness, by providing each apartment with only a transmitter and a loud speaker unit, both of whichare preferably built-in, and by so associating all of the loud speaker units with one centrally located sound producing device and associated pick-up element, such as a chime and an associated car con button transmitter, that any said loud speaker unit may he caused to reproduce the sound emitted bythe sounding device or chime, in response to the usual push-button apartment selection made hy the caller at the entrance to the apartment, The system is further so arranged; that the occupant thus called may thereafter employ transmitter and loud speaker unit for carrying on a two-way conversation with the caller, who has access to a telephone set at the entrance for thispurpose.

Claims. ((31.179-2) The sounding device or chime and'associated pick-up element or carbon button transmitter, may be mounted for example in thebasernent of the building, the pick-up device serving to convert the sounds emitted-thereat into correspon'd- 5 ing electrical oscillations for actuation of the. loud speaker unit in the apartment selected by the caller, Connection of the pick-up device to a desired apartment loud speaker unit and actuation of the sounding device to call the occupant,

is effected, under control of thecaller, by a series of relays which are selectively actuated by depression of the apartment push buttons mounted at an entrance to the building,such as in the visitors vestibule or at the tradesmens entrance. Preferably also a switch is provided in each apartment, actuation of which serves to disconnect the signaling-circuit aforesaid from the loud speaker and to connect the transmitter and loud I speaker unit with the telephone set at the en trance'to the building whereby the caller may converse with the apartment occupant.-

As a further refinement, the system of my invention may be extended to employ several cen trally located sounding devices each having a distinctively different sound, such as a bell, buzzer and a chime, each under control of a different series of apartment push-buttons disposed at various points about the building from which it is desired to originate calls, as in the visitors vestibule, at the tradesmens entrance, and in the superintendents office, the different sounding devices thus selectively actuated serving thereby to indicate to the apartment occupant the source from whence the call originates. Where a system of this characteris to be installed, the electrical circuits are of course appropriately modified, as will be explained, to assure that the proper sounding device will be, caused to actuate the selected apartment loud 4o speaker unit in accordance with the source from whence the call originated, and also to permit the'apartment occupant called to converse- 17818". phonically with the party initiating the signal.

Referring now to the drawings for a more detailed explanation of the invention:

, Fig. 1 is a diagrammatic representation, largely'in the form of an electrical circuit diagram,

of a' preferred modification of the invention in accordance with that first referred to wherein a single sounding device is employed for actuating.

any desired apartment loud speakerunit in response to push-button selection; while Fig. 2 is a similar diagrammatic representation of the more elaborate modification last referred in accordance with the invention is equipped with a transmitter T1, T2, T3 and a loud speaker L1. L2, L3, and also with a switch S1, S2, S3. The rectangle V represents an entrance to the apartment, such as the visitors vestibule, which is equipped with a telephone set including a transmitter T4 and receiver R4, and with a series'of push-buttons P1, P2, Ps, one for each apartment, for initiating a call to any of the various apartments at the option of the caller. The dashed rectangle 0 represents a centrally located portion of the building, such as the basement, where a single sound producing element, in this case a chime S, is mounted together with an associated pick-up element or transmitter T5, and a series of relays R1, R2, R3 and R4 for connecting the pickup element T5 to the selected loud speaker unit L of the apartment selected and for thereafter actuating the sounding device S.

For an understanding of the circuit connec tions and operation of the system, assume that a caller in the vestibule V desires to call apartment A1. To do this he momentarily depresses the corresponding push-button P1 which closes a circuit from the positive terminal of a battery I over conductor 2, through relay R4 and the contacts of push-button P1, the winding of relay R1 and thence back to the negative terminal of battery over conductor 3. Closure of this circuit operates relays R1 and R4, which thereafter release following release of the push-button. Operation of relay R1 closes a circuit to energize the pick-up device T5, this circuit being traced from the positive terminal of battery i over conductor 2 through the middle front contact and armature of relay R1, the primary winding of a transformer l, through the pickup device T5, and back to the negative terminal of the battery over conductor 3. Operation of relay R1 also closes a circuit connecting the secondary winding of transformer 4 to the loud speaker unit L1 in apartment A1, this circuit being traced from the lower terminal of this secondary winding over conductor 5, through the outer front contact and armature of relay R1, over conductor 5, through the upper contact and movable arm of switch S1, in apartment A1, thence through the winding of the associated loud speaker L1. and back to the secondary winding of transformer 8 over conductors l and 8. Closure of the circuits above described thus prepares the loud speaker L1 of apartment A1 to reproduce any sounds emitted by the centrally located chime S.

Operation of the chime is brought about by operation and release of relay R4, which completes a circuit traced from the secondary winding of a transformer I53, energized from a source of alternating current H, through the armature and front-contact of relay R4 and thence through the winding of a solenoid i2 for actuating the chime,

back to the secondary winding of trans-- former Id. The resulting energization of the solenoid 32 causes its armature i3 to be elevated and to strike against the upper sounding element i l of the chime, the solenoid being immediately thereafter released by release of relay R4, causing the armature it to fall away and strike against the lower sounding element i5, whereupon the armature is returned to its normal position as shown by the resilient action of springs H5 on which the armature is supported in the manner indicated. The sounds thus emitted by the chime are picked up by the transmitter T5 and converted into corresponding electrical oscilla'- tions, which are relayed to the loud speaker unit L1 over "the circuits above traced, thereby causing these sounds to be reproducedby this loud speaker unit.

As explained above, relays R1 and R4 are operated for only a short interval, since their operating circuit above traced is opened upon release of push-button P1, To assure that relay R1 will be operated for a sufficient interval to transmit the sustained notes of the chime to loud speaker L1 even though the push-button is depressed but momentarily, the release of this relay is retarded by condenser 9 which is connected through the inner front contact and armature of relay R1 across the relay winding upon operation thereof. Preferably also relay R4 is adjusted to operate slightly after relay R1 operates, to assure that loud speaker L1 is connected to pick-up device T5, and this device energized, before the chime is actuated.

Battery i may of course be substituted by a power pack, such as a dry rectifier, for supplying rectified direct current from the usual source of alternating current socket power.

A similar sequence of operations to that above described, would have occurred to actuate the loud speaker unit in either of apartments A2 or A: had the corresponding push-buttons P2 or P3 been initially depressed by the caller, the only difference in operation being that in such case relay R2 or R3 would operate instead of relay R1 to connect the pick-up transmitter T5 to the loud speaker unit L2 or L3, actuation of such loud speaker thereafter being the same as that described for apartment A1.

Reverting now to apartment A1, loud' speaker unit L1 of which has been actuated by the chime as described, the occupant on being called will depress the push-button S1 to connect the transmitter and loud speaker T1, L1 to the telephone set T'4, Ri, in the vestibule below for purposes of conversing with the caller, who of course for this purpose, removes the receiver R4 from its switch hook. With the circuit as thus arranged, the transmitters T1 and T4 are energized from the battery i, the former over a circuit traced from the positive terminal of 'thebattery over conterminal. Due to the fact that the energizing current for transmitter T1 traverses the induction coil is connected to receiver R'4, and to the fact that transmitter T1 is coupled through induction coil 22 to the loud speaker L1 over conductors l and 2! and through contacts of switch S1, the circuits are thus arranged for two-way conversation between the vestibule telephone set and that of apartment A1. When the call as thus initiated is consummated, the caller returns the receiver R4 to its switch hook, and the occupant of apartmerit A releases switch S1 whereby the circuit is restored to normal. Had the apartments A2 or A3 been called, the procedure for carrying on conversation with the caller would have been the same except that the occupant of the apartment called would have operated switch S2 or $3.

It will be. understood of course that in Fig. 1 only three apartments A1, A2, A3 and their associated signaling and telephone circuits have been shown merely for convenience, and that the system can be extended to embrace any number of apartments by merely providing additional equipment of the character described and multiplying the same in the manner shown.

Fig. 2 illustrates an extension of the system described in Fig. 1, to permit of initiating calls to the various apartments from any of several sources, such as from the visitors vestibule, tradesmens entrance, superintendents oflice or from the immediate entrance toeach apartment, and for producing a distinctively different sound on the loud speaker unit of the apartment called for each different source from which a call may be thus originated.

The apartments A1, A2, etc. are provided with loud speaker units, transmitters and switches L, T and S as in Fig. 1. Also the visitors vestibule V is provided with the push-buttons P1, P2, etc. and a telephone set RM, Ti, as aforesaid. In addition a tradesmens entrance H is provided at which the push-buttons P1, P8, etc. are multipled and which is also provided with a telephone set Ts, R5. An apartment may be thus called from either the visitors vestibule or from the tradesmens entrance. Also the immediate entrances to the individual apartments A1, A2, etc. are provided with push-buttons, P10, P11, etc., for signaling from these points. In addition the superintendents ofiice S is provided with a telephone set Ts, R6 andfwith a gang switch 36, whereby the superintendent may communicate either with an apartment or with the visitors vestibule.

The centrally located station is in this case provided with three distinctively different sound producing devices, namely, a chime S, bell R. and buzzer B, the chime being arranged to respond to calls initiated from the visitors vestibule, the buzzer to calls originating at the tradesmens entrance, and the bell to calls originating at the immediate entrances to apartments.

Each of the sound producing devices S, R. and B, has associated therewith a pick-up element or transmitter T5, T6, T1, for converting the sounds emitted by their associated sounding elements into corresponding electrical oscillations, which are relayed through a common transformer 4 to the loud speaker of the apartment called. Connection of the appropriate pick-up element to the loud speaker called, and subsequent operation of the associated sound producing device, is under control of the relays R1, R2 and R1, R8, R9 which in turn are under controlof the push-buttons P1, P2, etc., P7, Pa, etc.; P10, P11, etc.

For an understanding of the circuits and operation of the system, assume that a call originates in the apartment vestibule, by depression of push-button P1 to call apartment A1. Closure of push-button P1 completes a circuit for operation of relays R1and R1, this circuit being traced from the negative terminal of battery I over conductor 3!, through the winding of relay R1, thence over conductor 32 and through the contacts of push-button P1, thence over conductor 33 and through the winding of relay R1 to the positive terminal of battery I over conductor 34. These relays are thus operated for but a short interval and release again following release of the push-button.

I Operation of relay R1 connects transmitter T associated with chime S to battery I over a circuit traced fromthe negative battery terminal through theprimary-winding of transformer 4, through transmitter T5, over conductor 35, through the middle front contact and armature of relay R1 and back to the positive terminal of battery I, over conductors 36 and 34. Operation of relay R1 also completes a circuit from the secondary winding of transformer 4 to the loud speaker unit selected, in this case L1, this circuit being traced from the upper secondary terminal over conductors 31 and 38 through the winding of speaker unit 111 and the upper contacts of switch S1, thence over conductors 39, it and 32, and through the outer armature and front contact of relay R1, returning to the secondary winding of transformer 4 over conductor :2. Relay R1 is preferably designedto operate shortly after completion of the circuits thus traced to energize the chime S over a circuit traced from one terminal of the alternating'current source II, through the solenoid winding of the chime,- and thence through the. armature and front contact of relay R1, returnin'g'to the opposite terminal of the source 'II. Energization-of' this chime causes the loud speaker unit L1 to reproduce the sounds thereof by virtue of the pickup action of the associa'tedtransmitter T5, the signals of which are relayed through the winding of transformer 4 to the speaker unit over the circuits above traced. 1

The occupant of apartment A upon being thus called to thephone, depresses switch S1, which disconnects at its upper contacts the circuit traced through contacts of relay R1 and connects, througlrits lower contacts, the apartment phone T1, L1 with the vestibule phone T4,:R'-1. The transmitters T1 andT4 are thus energized over a circuit traced from the positive terminal of battery I, over conductors 43, 44, 45' and 46, through the lower left contacts of switch S1, where the current divides a portion flowing through transmitter T1 and thence through the lower right contacts of switch S1, over conductor ll and contacts of the gang switch 30, over conductor 28 and through the primary. winding of induction coil 19 in the vestibule telephone set, to the lower terminal of transmitter T1, where the current unites again withthe remaining portion which flows from the point of division 'referred to at switch S1, over conductor 50 and through the primary winding of the vestibule telephone set induction coil 5i and over conductor 53, through contacts of the gang switch 33 to conductor 53,- and through the transmitter T4,

where the current thr ough this transmitter units as aforesaid with that flowing through transmitter T1, the combined current thereafter returningto the negative sideof the battery I, overconductor 54, through the lower contacts of the tradesmens telephone set, returning thence to the negative side of battery I, over conductor' 56 It will be observed that in the transmitter energizing circuits above traced, the current for the vestibule transmitter Tr flows through the primary of induction coil 5!, to the secondary of which the apartment loud speaker unitslare connected, over the circuit comprising conductors 38 and till and. lower left contact of switches S,so that when the vestibule transmitter is spoken into the corresponding sounds are reproduced by the apartment loud speaker L cor- 1 l energizing current for the apartment transmitter T1 flows through the primary of induction coil 2-9, so that when this transmitter is spoken into the corresponding sounds are reproduced by the vestibule loud speaker R4 connected to the secondary of induction coil 49.

It will be understood of course that had the caller originally depressed push-button P2 instead of P1, to initiate a call to apartment A2, the operation of the system would be essentially the same as that above described with the exception that in this case relays R2 and R7 would have seen operated at the centrally located station to call apartment A2 in the manner described for apartment A1.

To assure that relay R1 or R2 as the case may be, remains operated for a sufficient interval to reproduce the sustained note of the chime by the apartment speaker selected, irrespective of the rapidity with which the push-button P1 or P2 is released, the release of these relays is retarded by the condenser M, which upon actuation of either of these relays, is shunted across its winding over a circuit traced through its inner armature and front contact.

Should the call originate at the tradesmens entrance depression of push-button P7 or Pa will operate relay R1 or R2 to connect the circuit of the pick-up device T2 associated with the buzzer B, with the apartment desired, and will also operate relay R8 to actuate the buzzer to produce a corresponding signal at the apartment coiled. Assume for example that push-button P7 is actuated. This completes a circuit to operate relays R1 and Rs, traced from the negative terminal of battery I, over conductor 3! and through the winding of relay R1, through the contacts oi push-button P1 to conductor 57, thence through the winding of relay R3 to the positive side or" battery l of the conductor 34. eration of relay R1 completes the circuit above described for connecting the secondary winding of transformer 4 to the called apartment A1; while the accompanying operation of relay R2 completes a circuit through its outer armature and front contact from the voltage source H to actuate the buzzer B; and also completes a circuit through its inner armature and front contact from the battery l to energize the pick-up transmitter T7, associated with the buzzer B, whereby the sounds produced by the buzzer are reproduced on the loud speaker at apartment A1.

When the apartment answers by depression of switch S1 thereat, the tradesmens telephone T5, upon removal of the receiver thereof from switch hook, is connected to the apartment telephone for intercomrnunication. Thus the apartment transmitter T1 and the tradesmens transmitter T5 are energized over a circuit traced from positive terminal of battery I, over conductors &3, M, =25 and 46, to the lower left contacts of switch S1, where the current divides, a portion flowing over conductor 50, through the primary winding of induction coil 5,! and through transmitter T5, returning to the negative side of battery l over conductor 56, and the remaining portion flowing from the point of division switch S1, through transmitter T1, the lower right contacts of switch S1, over conductor 41, through contacts of the gang switch 30 to con ductor d8, thence over conductor 58, through the upper right switch hook contacts 59 of the trades-' mens telephone set, and through the receiver R5, returning to the negative side of the battery over conductor 56. It will be observed in the circuits The opabove traced that the current for transmitter T5 flows through the primary of induction coil 5| connected to the apartment loud speaker units L1 and L2, over conductors 33 and 50, so that when the tradesmens phone is spoken into the loud speaker unit at the apartment called, namely L1, will be energized to reproduce the sounds thereof. Likewise the current for the apartment transmitter T1 flows through the tradesmens receiver unit R5, so that when transmitter T1 is spoken into the sounds will be reproduced by the tradesmens receiver, so that telephonic conversation between the parties may be carried on.

Should a caller wish to announce his presence at the immediate entrance to one of the apartments, he may do so by pressing push-button P or P11 at the apartment entrances respectively. This will energize relay R1 or R2, as the case may be, at the centrally located station C and will also energize relay R9 thereat, to actuate the. bell R, and to connect its associated pick-up elements Ts, through transformer l, to the loud speaker unit of the apartment corresponding to the push button P10 or P11 which is actuated.

Assume for example that apartment push-button P10 is depressed. This completes a circuit to operate relays R1 and R9, traced from the negative terminal of battery I, over conductor 3|, through the winding of relay R1, over conductors 32 and 48, through the contacts of push-button P10, thence over conductor 60, and through the winding of relay R9 to the positive terminal of battery I over conductorfi l. Relays R1 and R9 will thus be energized, relay R1 to complete, at its terminals, the circuit above traced for connecting the secondary winding of transformer l to loud speaker unit L1 of apartment A1. The operation of relay R9 in turn connects, through its outer front contact and armature, the voltage source 5 l to the bell R, thereby to energize the same; and also connects through its inner front contact and armature, battery I to the pick-up device Ts, whereby the sounds produced by the bell R are relayed by means of the pick-up device T6 and the transformer t to the loud speaker unit of apartment A1. Owing to the distinctive sound produced by the bell, the occupant knows that the caller is at the apartment door rather than in the vestibule or at the tradesmens entrance, and responds accordingly.

The superintendents phone Ts, R6 is arranged by means of the gang switch 3i) for communication either with the vestibule phone T'4, R'4 or with any of the apartment phones. With the gang switch in its normal position as shown in the drawings, the superintendents phone is connected for communication with the vestibule phone.

For initiating a call from any apartment or from the vestibule to the superintendents office,

each apartment and the vestibule may be provided with a push-button circuit, closure of which operates a signal in the superintendents office. This circuit is not shown as it is merely a standard form of circuit, consisting of a signaling device, such as a bell mounted in the superintendents o-flice and energized from source I I upon closure of an apartment or vestibule push-button, the contacts of which for the various apartments and the vestibule, are wired in multiple, so that closure of any one will complete the ringing circuit. It is not ordinarily required that the superintendent be enabled to signal the various apartments from his office, but should this be desired it would merely be necessary to provide his oflice with a series of push-buttons corresponding to the apartments and to connect'these push-buttons to circuits identical with those provided in the case of the vestibule and at the tradesmens entrance, whereby the superintendent could produce a distinctive tone at the apartment called in the manner above described for the systems of the vestibule and tradesmens entrance. The circuits whereby the superintendent could so signal the apartments have accordingly not been omitted in the interests of simplicity.

Assuming that the caller in the vestibule has signaled the superintendents ofiice, the superintendent responds by removing his receiver from the switch hook, thereby to connect his telephone set with the vestibule set. Thus the transmitters T5 and Te will be energized over a circuit traced from the positive terminal of battery I, over conductors 4.3, M and 45, where the current divides, a portion flowing to the receiver Rs, through contacts of the gang switch and the right hand contacts on the switch hook and thence through other contacts of the gang switch and over conductor 6!, through the primary winding of induction coil 5!, over conductor 52, and through contacts of the gang switch to conductor 53, through transmitter T'4, returning to the negative side of the battery over conductor 5d normally closed contacts 55 at the switch hook of the tradesmens phone and conductor 55; the remaining portion of the current in conductor 15 flowing through contacts of the gang switch, transmitter T6, and contacts of the associated switch hook to conductor 48, and through the primary winding of induction coil 49 to the negative side of transmitter T'4, returning therefrom to the negative side of battery l over. the circuit above traced.

It will be thus observed that the energizing current for transmitter T4 flows through the superintendents receiver Rs, so that whenithe vestibule phone is spoken into the sounds will be reproduced by the superintendents receiver. Conversely the energizing current for the superintendents transmitter Ts flows through the primary winding of induction coil 49, so that when the superintendents phone is spoken into corresponding sounds will be reproduced by the vestibule receiver 3 4, which is connected to the secondary winding of induction coil 49.

With the gang switch 38 operated to the left, and with one of the apartment switches, such as S1, depressed, the superintendents telephone set is connected to the corresponding apartment telephone set for intercornmunication,'v over the following circuits. The transmitters T1 and T6 are energized over a circuit traced from the posi-- tive terminal of battery I, over conductors 43,44, 5 and 46 to switch S1, where the current divides, a portion flowing through the left hand lower contacts of switch S1, through transmitter T1 and thelower right hand contacts of switch S1, over conductor ll and through contacts of the gang switch 30 to conductor 62, thence through other contacts of the gang switch, through receiver Re, the right hand switch hook contacts of the superintendents phone, through other contacts ofthe gang switch to conductor 63, and thence to the negative terminal of battery I. Reverting to switch S1, the remaining portion of the current flowing over the circuit traced to conductor 46, from the positive terminal of battery I, flows throughthe loud speaker L1 and thence over conductor 38, through the secondary and primary windingsof induction coi1 5l to conductor 52,

and thence through the left hand contacts ofthe gang switch 36, and through switch hook contatcts of the superintendents telephone set to transmitter T6 and through this transmitter and contacts of the gang switch 30 to conductor 63,

returning thus to the negative terminal of bat,- 1 tery l as aforesaid.

It will be noted in the circuits above traced that the energizing current for the superintendents transmitter ,T6 flows, through the loud speaker L1, and that conversely the energizing current for the apartment transmitter T1 flows through the superintendents receiver Re, so that when these transmitters are spoken into the sounds are. reproduced on the appropriate receiver units for establishing two-way conversation between the superintendents phone and that,

of the apartment.

I- claim 1 1. In a selective signaling system: a sound producing element, a pick-up'device thereat for converting said'sound into corresponding electrical oscillations, a plurality of sound reproducing ele- ,ments, a plurality of relays individual thereto,

connections .from said pick-up device to each ofsaid sound reproducing. elements through contacts of its associated relay, switching means for selectively actuating any of said relays thereby to connect said pick-up device to the associated sound reproducing element, and means responsive to actuation of said'switching means for actuating said sound producing element.

2'. In a selectivesignaling system: a sound producing element, a pick-up device thereat for converting said sound into corresponding electrical oscillationa-a plurality of sound reproducing elements, a plurality of relays individual thereto, connections from said pick-up'device to each of said sound reproducing elements through contacts of its associated relay, switching means for selectively actuating any of said relays thereby to connect said pick-up device to the associated sound reproducing element, and means including an additional relay responsive to actuation of said switching means for actuating said sound producing element.

3. In 'a selective electrical signaling and cornznunicating system: a sound producing element and associated pick-up device, a plurality of j transmitting and receiving units, selective switching means and means controlled thereby for connecting said pick-up device to any of said receiving units, means responsive to actuation of said switchingmeans for 'energizing'said sound producing element, an additional transmitting and receiving unit at said switching means, and

means including a switch at each of said plu rality of transmitting and receiving units for establishing a two-way talking circuit between;

the associatedtransmitting and receiving unit and s-aid'additional transmitting and receiving unit. v

4; Ina selective signaling system: a plurality of electrically actuated sound producing elements, each productive of adistinctively different sound; pick-up means thereat for converting said sounds into corresponding electrical oscillations; a plurality of sound reproducing elements; a plurality of sets of selective switching devices and means controlled thereby for connecting by appropriate actuation of a switching device in any said set, said pick-up means to any said sound,

reproducing element, and for actuating one of said sound producing elements, the particular sound producing element so actuated being determined by the particular set containing the switching device so actuated.

5. In a selective signaling system: a pluralityv of sound reproducing elements; a plurality of electrically actuated sound producing elements, each productive of a distinctively different sound; pick-up means for converting said sounds into corresponding electrical oscillations; a like plurality of selective switching devices, and means controlled thereby for connecting by appropriate actuation of a switching device in any said set, said pick-up means to any said sound reproducing element, and for actuating one of said sound producing elements, a diiierent such .element responding to actuation of switching devices in each said set. r

6. In a selective electrical signaling and communicating system: a plurality of electrically actuated sound producing elements each productive of a distinctively different sound; pick-up means for converting said sounds into corresponding electrical oscillations; a plurality of remotely located signal receiving stations each equipped with a transmitting and a receiving unit; means including a switch adjacent each said signal receiving station for connecting said pick-up means to said station and for actuating oneof said sound producing elements to produce a corresponding sound at said station; a plurality of selecting stations remote from saidsignal receiving stations; means including a selective switching device at each of said selecting stations for connecting said pick-up means to any said signal receiving station and for actuating one of said sound producing elements, a different said sound producing element for each said selecting station; and means including a telephone set at each of said selecting stations and a switch at each of said signal receiving stations for establishing a two-way talking circuit between any said selecting station and the signal receiving station selected thereby.

7. In a selective electrical signaling and commtuiicating system: a plurality of electrically actuated sound producing elements each productive of a distinctively different sound; pick-up means for converting said sounds into corresponding electrical oscillations; a plurality of remotely locate signal receiving stations, each equipped with a transmitting and a receiving uni means including a switch adjacent each said signal receiving station for connecting said pickup means to said station and for actuating one of said sound producing elements to produce a corresponding sound at such station; a plurality of selecting stations remote from said signal receiving stations; means including a selective switching device ateach of said selecting stations for connecting said pick-up means to any said signal receiving station and for actuating one of said sound producing elements, a different said sound producing element for each said selecting station; means including a telephone set at each of said selecting stations, and a switch at each of said signal receiving stations for establishing a. two-way talking circuit between any said selecting station and the signal receiving station selected thereby; an additional station equipped with a transmitting and receiving unit; and

means including a switch thereat for establishing a two-way talking circuit between the transmitting and receiving unit at said station and the transmitting and receiving unit at any of said signal receiving stations and alternatively with thetransmitting and receiving unit at at tively connecting said pick-up device to any of said sound reproducing elements, means responsive to actuation of said switching means for actuating said sound producing element, and means independent of said switching means for maintaining the connection of said pick-up device to a sound reproducing element for an interval suiilcient to permit the transmission of a sustained note from the sound producing to the sound reproducing element so connected.

9. In a selective signaling system: a sound producing element, a pick-up device thereat for converting said sound into corresponding electrical oscillations, a plurality of sound reproducing elements, a plurality of relays individual thereto, connections from said pick-up device to each of said sound reproducing elements through contacts of its associated relay, switching means for selectively actuating any of said relays thereby to connect said pick-up device to the associated sound reproducing element, means responsive to actuation of said switching means for actuating said sound producing element, and means including a condenser and contacts of said relays for maintaining the connection of said pick-up device to a sound reproducing element for an interval sufiicient to permit of transmitting a sustained note from the sound producing to the sound reproducing element so connected.

10. In a selective calling system: a plurality of sound reproducing elements, a plurality of switches individual thereto, electrical conductors permanently extending between each said switchand its associated sound reproducing element, an electrically actuated sound producing element, a pick-up device thereat for converting said sounds into corresponding electrical oscillations, and means responsive to operation of any of said switches for actuating said sound producing element and for transmitting the corresponding electrical oscillations from said pick-up device to the reproducing element associated with said- SWTW 'I.

CHARLES AUTH. 

